I knew that you could get low normal rear mechs, but every MTB I have ever had has always had a high normal rear mech – so I gathered they were a roady thing, or something from the 80's!!

Anyway, building a bike up for my other half, and part of the build was a load of bits I got with a frame I bought, namely the rear mech. Noticed that it was on lowest gear at rest. Looked it up – RD-M760, yep, low normal, a bit of reading around said they are usually suited to dual control levers. I also had some Shimano dual control levers in my pile of bits, so gathered it was the norm.

Cabled it all up, etc – nope, the dual controls shift just like any other rapid fire shifter. So now I have a shifter that shifts down, with a mech that shifts up!!

Not a major worry, I'll probably replace the mech anyway as it has some play in the pivots, but it may confiuse the missus a bit!!

So, why low normal? And are they still common?

I'm not sure what you're asking TBH. Low normal (rapidrise) is a fairly recent thing and AFAIK wasn't very common?

Not as common as they should be – in my opinion they should be the way all rear mechs work – you use the spring tension to help shift the chain to a larger cog – which makes a lot more sense as there is more 'power' helping the shift. It's much easier and requires much less effort to move a chain from a larger to smaller cog so this doesn't really need sprint tension to help it…going the other way does require more effort so the spring can help with it.

If you only have 1 bike then low normal very quickly becomes dead easy and natural to use – if you have more than 1 bike then it's going to be a pain to get used to as instinctively you will try to shift up and press the wrong lever – so decide if you like it and make all your bikes the same.

It just alters the way the shifter shifts. Shifter remains the same and you can use either Dual Control or Rapidfire Plus but the action will be reversed if you fit a low-normal (aka rapid-rise) mech to it. Personally I can't stand the things and always use high-normal mechs (that drop you into the highest gear if the cable is loosened), have done on both RF+ and DC shifters.

they are becoming less common because they are pish.

Actually they've been around for ages, there was an M952 Rapid Rise mech. When Shimano came out with Dual Control in 2003 they decided it was particularly suited to RR (Low normal), and as such they only offered the M960 rear mech in low normal.

When they revamped XT they did the same, but they offered a top-normal XT mech too to appease the nay-sayers, and to match the Rapid Fire shifters.

There are still folk who will swear by low normal, they will work with any shifters you like, but will always invert the lever functions. It's not, and never has been, a road thing.

you use the spring tension to help shift the chain to a larger cog – which makes a lot more sense as there is more 'power' helping the shift.

I find that my thumb has far more power to shift the chain than any spring could have.

There is nothing inherently wrong with low normal, it's just that it offers no advantages over high normal and is therefore an answer to a question nobody asked.

The main benefit of rapid rise is you can shift smoothly to an easier gear under hard load which comes in useful for, oh I dunno, climbing steep hills..

Always used normal mechs before wouldn't use anything but rapid rise now.

I find that my thumb has far more power to shift the chain than any spring could have.

There is nothing inherently wrong with low normal, it's just that it offers no advantages over high normal and is therefore an answer to a question nobody asked.

+1.

Haha, sorry, I guess my post ended up being more a rant than a meaningful post!!

I suppose it just bugs me when companies do this, you have a std, then they offer an alternative.

Just been out on it, and tbh, it didn't take me any time at all to adjust, but it will be confusing for my gf, who is an MTB novice, especially when the shifters do the reverse of what they say they do, and the index window is showing the wrong gear!!

Just wondered why Shimano suggested they were better suited to dual controls, as the dual controls I have here, shift like rapid fire, and so no different to the 'norm', and so not ideal for low normal mech.

Anyway, the mech is going. I can see the logic with down shifting under spring tension for speed and ease, but me personally, if I need to shift down quickly, I like to do it a few cogs at a time, in one long push of the shifter, not three little clicks!!

High normal for me 🙂 No fun in having one odd bike!

On the upside, she was pretty happy with her 'new' bike, and got on quite well considering she hadn't ridden a bike for probably 20 years!!

I got on quite well with low normal. I liked being able to dump gears at the bottom of a climb with a few quick clicks. In some ways it is more intuitive that top normal. I soon ditched it when I got a second bike that was top normal. Whatever the pros and cons of both systems, it is a nightmare moving from one to another.

Most folk think low normal is all wrong as they are conditioned to top normal – so anything that isn't top normal is clearly bad…to be honest it's personal choice…it works for me and I reckon it's far better than top normal…but one of my best riding buddies swears blind by top normal (bought a bike from the shop and downgraded the rear mech to top normal as he didn't want low normal – each to their own).

Top normal has always been the way mechs have worked…low normal (or Rapidrise has been around for a good few years but it doesn't work like top normal so most folk don't like it (and hence don't buy it).

I think that's part of the reason that Dual Control never caught on as well because Shimano kept saying that it was "more suited" to being used with Low-Normal – people didn't like rapidrise mechs and were quite happy to stick with RF+ and high-normal so rapidrise and DC is now much harder to sell (and hardly any bikes have it specced OEM). You only have to look at DC and rapidrise on CRC/Wiggle to see how much the price has fallen as they try to get rid of old stock.

I think it's one of the rare examples of Shimano not publicising it properly (bit like BioPace really).

But I still can't see why rapid rise is better suited to Dual Control, unless the Dual Control levers I have are old, and newer ones suited to rpaid rise.

The Dual Controls I have, have the same shift action as rapid fire??